A passenger jet carrying 49 people crash-landed in South Sudan's north-western city of Wau today, but all passengers and crew survived, said an airport official.

The plane was landing but then crashed, said Wau's Acting Airport Manager Stephen Youngule.

"The weather is not good. Visibility was not good up to now and (the plane) was landing from the east to west then it just crashed (off) the runway. The pilot I think was not seeing the runway well," Paul Charles, an engineer at Wau airport, said

"The plane touched down and then jumped up again. The pilot couldn't control it," said Youngule, who is also Deputy Director of Air Traffic Services.

"I saw it until the very last moment before the fire engulfed the aircraft," he said.

When the plane crashed, its door flew open, which allowed the pilot and rescue crews to get everybody out, he said. Those with injuries were taken to Wau's hospital for treatment, said Youngule.

The plane carried 44 passengers and had five crew members, said Youngule.

"Right now we have the ambulance which has just come out from the airport and we have received 14 patients being rushed to hospital in stable condition," said State Information Minister Bona Gaudensio.

On social media, images appeared of the plane with smoke billowing from the wrecked fuselage.

The plane was from South Supreme Airlines, a South Sudanese carrier. It was making a trip from Juba to Wau, in northwestern South Sudan when it crashed. Most of the passengers were South Sudanese with two foreigners, one each from China and Eritrea.

Since 2013, South Sudan has been embroiled in a civil war that has killed at least 50,000 people. In late February, a famine was declared in the country and more than 1 million people are at risk of starvation.